1. Field
The aspects of the disclosed embodiment generally relate to robotic systems and, more particularly, to robotic transport apparatus.
2. Brief Description of Related Developments
In, for example, the semiconductor manufacturing industry workpieces or semiconductor substrates may be processed in linear tool system and/or cluster tool system that have side-by-side substrate holding stations. Generally, in these systems having side-by-side substrate holding stations semiconductor manufacturers request independent radial robots capable of transferring the substrates to and from the side-by-side substrate holding stations at substantially the same time or independently. Generally this has been done by providing two transfer arms having spacing between the transfer arms that is substantially the same as the spacing between the side-by-side substrate holding stations. These transfer arms may be mounted on a boom arm or a linear slide. These transfer arms may also employ linear drives for extending and retracting the arms to and from the substrate holding stations.
It would be advantageous to provide a single robot configured with two side-by-side independent arms, each arm being configured to operate on a common axis of rotation while having independent rotary motor actuation along a respective radial axis. It would also be advantageous to provide a single robot configured with two independent arms, each arm being configured to operate on a common axis of rotation while having independent rotary motor actuation along a common radial axis. It would also be advantageous to provide each of the side-by-side independent arms with movement in a direction that is substantially normal to movement of the side-by-side independent arms along the radial axis to effect the ability to correct for system station errors while also effecting the ability to correct wafer placement using on-the-fly technology without using a theta axis of the transfer robot.